The present disclosure relates generally to an imaging reader for, and a method of, reading a target, such as a bar code symbol, to be electro-optically read by image capture over a field of view through a window that environmentally seals the imaging reader, and, more particularly, to an optical system having one or more optical elements that are integrated, and are of one-piece construction, with the window for optically modifying light, such as aiming and/or illuminating lights, that pass through the optical elements.
Solid-state imaging readers have long been used, in both handheld and hands-free modes of operation, in many industries, such as retail, manufacturing, warehousing, distribution, postal, transportation, logistics, etc., to electro-optically read targets, such as one- or two-dimensional bar code symbols to be decoded. A known imaging reader generally includes an aiming light system for directing one or more visible aiming lights through a window to a target to visually locate the target and, thus, advise an operator which way the reader is to be pointed in order to position the aiming lights on the target, prior to reading; an illuminating system for emitting one or more illuminating lights through the window toward the target to illuminate the target, especially in dimly lit environments; an imaging system for capturing an image of the target through the window over a field of view; and an object/target sensing system for activating the reader when the target enters the field of view. Each of these systems typically includes one or more optical elements. For example, the aiming light system may have one or more aiming lenses, and the illuminating system may have one or more illuminating reflectors.
Although generally satisfactory for their intended purpose, each such optical element is a discrete component that must be individually manufactured, sometimes being relatively expensive to fabricate, and be individually optically aligned when installed in the reader, thereby making them unsuitable for low cost, imaging readers. The installation of multiple optical elements can increase the tolerance build-up between components of the reader, thereby degrading the optical alignment. Moreover, light can reflect off surfaces of each such discrete optical element, for example, internally of the reader between the window and each such discrete optical element. Such internal light reflections can stray and migrate among the various systems, for example, to the imaging system, thereby degrading reading performance.
Accordingly, it would be desirable to reduce the number of components to be fabricated, installed, and optically aligned in the reader, to reduce the tolerance build-up between components of the reader, to simplify optical alignment, to mitigate stray internal reflections, and to improve overall reading performance.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and locations of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The window, reader and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.